1. Field of the Invention
The present invention relates to the technical field associated with portable terminal devices. More particularly, the invention relates to the technical field for contriving enhanced communication performance while securing sufficient rigidity of a casing of a portable terminal device by a configuration in which an operation unit formed from a resin material is disposed at a position, for covering an antenna, of a casing having a metallic casing body.
2. Description of the Related Art
Portable terminal devices include not only those which permit reproduction, viewing and listening, etc. of contents such as music and pictures but also those which enables information processing and the like, such as PDAs (personal digital assistants) and mobile phones.
Further, such portable terminal devices include those which have an antenna for permitting transmission and reception of information and, hence, have communication functions.
The portable terminal devices having communication functions may be classified into the type in which an antenna is drawn out to the exterior when used and the type in which an antenna is incorporated in a casing. In the type in which an antenna is incorporated in the casing, the antenna is mounted on a circuit board disposed inside the casing (see, for example, Japanese Patent Laid-Open No. 2007-67744).